ACOUSTIC REFRIGERATION -A DIFFERENT APPROACH IN CLEAN REFRIGERATION

fIRST tHE cONVENTIONAL sYSTEM :
Conventional refrigerators chill items by compressing and expanding chemicals called refrigerants. This transfers heat from inside the fridge to the outside, cooling the inside. Sound waves can do the same job: very powerful sound waves can also conduct heat. In an acoustic refrigerator, helium is compressed in a small steel cylinder to a pressure 10 times that of the Earth's atmosphere. Then a speaker blasts a long unchanging note, sending sound waves vibrating through the helium-filled cylinder.

prOCESS :

The pressure changes caused by the sound waves bouncing around in the sealed space alternately heat and cool the enclosed gas.




The sound waves force the helium through a fine-meshed stainless steel screen, and heat is transferred from the gas to the steel. As the sound passes through the screens, it causes the sound wave to drop in pressure. This causes the helium to expand and cool even more before it reaches a reservoir of ethyl alcohol.



The now-cold helium draws heat from the alcohol. The cold alcohol is then pumped through the walls of the refrigerator to cool the inside, and pumped back to the reservoir, where the helium chills it again.



Your ear works much like the acoustic refrigerator. Sound waves inside your ear vibrate the eardrum. As the eardrum swings back and forth, a fluid inside picks up those waves, just like the refrigerator's helium cylinder. Instead of turning the energy from the waves into heat, as the refrigerator does, the waves' energy vibrates tiny hairs that are tuned to the different pitches of the sound. The sound you hear consists of different frequencies or wavelengths, which determine their pitch.



Loud sounds can cause pain at 120 dB -- what you would hear near the stage at a heavy metal concern. At 165 dB, your hair would catch fire from the heat caused by the friction from the sound vibrations. Acoustic refrigerators have sound levels of 173-196 dB -- similar to the sound of a space shuttle launch at ground zero -- safely contained in a pressurized tube. Even if the tube shattered, the sound would instantly spread out through the atmosphere and return to harmless levels.

A BasIC pROCEedure :-

A cut-away solid model of the entire machine is shown Above and a cross-sectional view is shown on the left. The cold heat exchanger (dark grey) is identical to the hot heat exchanger and is contained within a thermally-insulating Ultem plastic plate (brown). The cold heat exchanger plate is in contact with the “platform” plate (yellow) that contains the regenerator and sensor signal lines. A second thermally-insulating Ultem plastic plate (green) provides the contoured plenum space that directs the oscillating cold helium gas in and out of the thermal buffer spaces (“windows”) through the platform. A solid stainless steel plate (dark grey) is used to seal the platform, cold heat exchanger plate, and plenum plate to the pressure vessel (green) and provide the force necessary to resist the 10 atmospheres of internal helium gas pressure. Enclosing the hot heat exchanger is the vibromechanical multiplier comprised of the compliance volume within the multiplier's cylinder (orange) that is terminated by an ordinary loudspeaker cone (purple). Directly below the speaker cone is the power piston cone (light green) that is attached to the bellows (gray). The moving-magnet linear motor, which moves the power piston cone, is shown as a gray rectangle with yellow straps. It is attached to the bottom plate (black) that forms the lower boundary of the pressure vessel. The cylindrical portion of the pressure vessel is shown in green.

***Due to my Lethargic writing speed you still need to wait for few weeks for complete post and soon u might see my own new comapct acoustic refrigerators design on this page ....yawnnnnnnnn

*** IMAGE COURTESY :Steven Garrett